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Access to unstable local variables that are not accessible from outside the function of the observed behavior in C ++?

In C ++ 03, Standard Observed Behavior (1.9 / 6) involves reading and writing volatile data. Now I have this code:

int main()
{
    const volatile int value = 0;
    if( value ) {
    }
    return 0;
}

which formally initializes the volatile variable and then reads it. Visual C ++ 10 emits machine code that makes a place on the stack by pushing the word dword there, then writes zero to that place on the stack, then reads that location.

This does not make sense to me - no other code or hardware can know where the local variable is (since it is in automatic storage), and therefore it is unreasonable to expect that the variable could be read / written by any other side and therefore it can be eliminate in this case.

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int _tmain(int argc, _TCHAR* argv[])
{
    int a; 
    //int volatile a;
    a=1; //break point here is not possible in Release build, unless volatile used

    printf("%d\n",a);
    return 0;
}
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